Pull down hardware



April 9, 1963 R. D. CARR PULL DOWN HARDWARE Filed Sept. 28, 1961 &

INVENTOR. Faber) D 54/7" flr/zz f :mquimmiimiiiiiiInn-(#5 United 6States Patent $084309 PULL DOWN HARDWARE Robert D. Carr, R0. Drawer1070, Victoria, Tex. Filed Sept. 28, I961, Ser. No. 141,518 1 Claim.(Cl. 254-51) The present invention relates to the formation ofprestressed concrete members such as beams, posts, piles, sleepers,tubes or the like, and the present invention is an improvement over thedevices shown and described in my prior co-pending patent applicationSerial No. 722,589, filed March 19, d958, and in my Patent No.3,013,322.

An object of the present invention is to provide an improved means fordeflecting the strands and wherein an actuating mechanism is providedconsisting of a hydraulic jack to provide the necessary force foraccomplishing the desired results.

Another object is to provide an apparatus of the character describedwhich consists of pull down hardware using a center hole jack, andwherein a hydraulic jack is adapted to be utilized.

Another object is to provide an apparatus of the character describedthat may be utilized speedily and with precision by even inexperiencedoperators.

Further objects and advantages are to provide improved elements andarrangements thereof in a device of the character described that iseconomical to produce, durable in form, and conducive to the mosteconomical use of materials and uniformity of members formed therefrom.

Still further objects and advantages will become apparent in thesubsequent description and specification.

In the drawings:

FIGURE 1 is a side elevational view illustrating pull down hardwareusing a center hole jack, and showing the position of the parts prior todeflection.

FIGURE 2 is a view generally similar to FIGURE 1, but with parts brokenaway and in section, and showing the parts in a different position afterdeflection of the strands or wires.

FIGURE 3 is a sectional view after the jack is removed.

FIGURE 4 is a sectional view taken through the completed pre-stressedconcrete article.

FIGURE 5 is a fragmentary sectional view illustrating certainconstructional details of the present invention.

FIGURE 6 is a sectional view taken on the line 66 of FIGURE 5.

FIGURE 7 is a fragmentary sectional view showing the ring raised abovethe split nut.

FIGURE 8 is a sectional view taken on the line 8-8 of FIGURE 7.

FIGURE 8a is a perspective view showing the parts of the split nutseparated.

FIGURE 9 is a fragmentary sectional view generally similar to FIGURE 7,but showing the ring on the split nut.

FIGURE 10 is a sectional view taken on the line 10-10 of FIGURE 9.

FIGURE 11 is a fragmentary elevational view, with parts broken away andin section, showing the connection of the stud to the anchor plate.

FIGURE 12 is a fragmentary sectional view on an enlarged scale showing aportion of the completed prestressed member.

Referring in detail to the drawings, and more particularly to FIGURES 1through 12 of the drawings, the numeral 30 indicates an anchor platewhich is provided with a threaded opening 31, FIGURE 3, and the numeral32 indicates a sealing element or neoprene seal which is arrangedcontiguous to the anchor plate 30. The numeral 36 indicates an elongatedstud which includes a lower threaded portion 34 that is arranged inthreaded ice engagement with the threaded aperture or opening 31 in theanchor plate 30, and the stud 33 further includes a non-threaded orsmooth portion 35 as well as an upper threaded section or portion 36,for a purpose to be later described.

As shown in the drawings, there is provided a sleeve 37 which is mountedon the lower portion of the stud 33, and the sleeve 37 has aflixedthereto or formed integral therewith a plurality of diametricallyopposed spaced apart lugs 38 for engaging therebelow strands or steelwires 39 which are to be deflected, and as shown in FIG- URE ;1initially the strands 39 have a straight formation, and after beingdeflected the strands are adapted to have inclined end portions 40 aswell as intermediate straight portions 41. In FIGURE 3, the numeral 42.indicates a portion of a mold or form which may have any desired shapeor configuration, and the mold 42 is shown to comprise spaced apart wallmembers 43. In FIGURE 4 the numeral 44 indicates the completedpre-stressed concrete article or member which is formed in accordancewith the present invention. It is to be understood however that theexternal shape or configuration of such a member can vary as desired orrequired, and the present invention is only concerned with thedeflecting and consequential final stage of pre-stressing of the strandsor wire members 39 in the concrete 45.

There is further provided a support member or tapered sleeve which isindicated generally by the numeral 46, and the member 46 is providedwith an elongated longitudinally extending bore 47 for the projectiontherethrough of a portion of the stud 33, and the outer portion of thesupport member 46 has a tapered formation whereby the upper end thereofis of greater diameter than the lower end so as to facilitate removal ofthe member 46 from the article to provide the space or recess asindicated by the numeral 54 in FIGURE 4. The upper end of the supportmember 46 may be provided with diametrically opposed openings 48, andthe numeral 49 indicates a housing that is arranged above the supportmember 46-, and the housing 49 is mounted on the stud 33, and thehousing 49 includes upper and lower portions 50 and 51 as well as anintermediate recessed portion 52 and side recesses or cutouts 53. Thenumeral 55 indicates a split nut which is adapted to be readily arrangedin the recess 52, and as shown in FIGURE 8a, the nut 55 includesseparate segments or pieces 56, and ring 57 is adapted to be arranged inengagement with the segments 56.

The numeral 58 indicates a center hole jack which includes a cylinder 59that is adapted to be connected to a suitable source of actuating mediumsuch as hydraulic fluid under pressure as for example by means of theconduit 60, and a vent or aperture 61 may be arranged in the lowerportion of the cylinder 59, FIGURE 2. The numeral 62 indicates a plungerwhich includes an upper piston portion 63 arranged for reciprocalengagement with the interior of the cylinder 59, and the plunger 62further includes a portion 64 above the housing 49.

As shown in FIGURE 1 for example, there is provided top nuts 65 and 66which are arranged in threaded engagement with the portion 36 of thestud 33.

In use, with the parts arranged as shown in the drawings and inparticular as shown in FIGURES 1 through 12 of the drawings, the jack 58can be used in conjunction with the other elements and the jack 58 maybe hydraulically operated by hydraulic fluid which can be supplied froma suitable source of supply to the interior of the cylinder 59 throughthe conduit 69, and FIGURE 1 illustrates the position of the partsbefore deflection of the strands or wires 39, while FIGURE 2 illustratesthe position of the parts after the deflection, FIGURE 3 shows the partsin position after removal of the jack, while FIGURE 4 shows thecompleted pre-stressed concrete member 44 which is adapted to be formedaccording to the present invention. As shown in FIGURE 4 the sleeve 37remains in the molded article or member 44, but the member 46 as well asthe stud 33 and its associated parts are removed from the completedmember 44.

The following is given as a detailed description of operation inconnection with FIGURES 1 through 12. In

order to deflect the stressing strands of the mechanism of FIGURES 1through 12 the following procedure is followed. Initially the two topnuts 65 and 66 are applied to the top of the stud 33 and lockedtogether. Then, the center hole jack 58-, the housing 49 and split nutring 57, the support member 46, the sleeve 37, and the sealing element32 are slipped onto the stud 33'. The bottom of the stud 33 is lowereddown between the stressing strand 39 and screwed into the anchor plate30. The sleeve 37 is positioned between the strands 39 and said strandsare hooked onto the lugs 38. Pressure is induced through the conduit 60'through the jack 58, and said jack pushes up against the nut 66 and downagainst the split nut housing 46, and in turn against the support member46, the sleeve 37, and the strands 39.

The distance from the lowest lug 38 to the bottom of the sleeve '37 issuch that when the strands 39 are pulled down to the final positions 4%and 41, the sleeve 37 is properly pressed into the sealing element 32.While the jack 58 holds the strands 39 in position, the split nut ring57 is raised and both halves of the split nut pieces 66 are arranged inthreaded engagement with the stud 33 and snug against the lower portion61 of the housing- 49'. Then, the ring 57 is slipped down over the splitnut pieces 56 and the pressure is released from the jack 58. While awrench applied to both nuts 66 and 65, the lower nut 66 is held and theupper nut 65 is removed, and then the lower nut 66 is removed. The jack58 is removed and this portion of the work is ready for the placement ofthe concrete 45.

After the concrete has hardened sufficiently, the top nuts 65 and 66 arereinstalled and, by applying a wrench to the lower nut 66, the stud 33,the split nut 55, and the housing 49 are removed. A round bar is adaptedto be passed through the holes 43 at the top of the support member 46.By the use of the handle thus formed a torque and an upward thrust areapplied to the support member 46 which is removed from the concretemember44.

Minor changes in shape, size and rearrangement of details coming withinthe scope of the invention claimed maybe resorted to in actual practice,if desired.

What is claimed is:

A device of the character described, comprising an anchor plate, asealing element of yieldable material contiguous to said anchor plate,an elongated stud including a lower threaded portion extending throughsaid sealing element, and threadedly engaging said anchor plate, saidstud further including a non-threaded smooth portion and upper threadedsection, a sleeve mounted on the lower portion of said stud above saidsealing element, a plurality of diametrically opposed spaced apart lugsaffixed to said sleeve and said lugs adapted to have steel strandsengaged therebelow; a support member positioned above said sleeve andsaid support member having a longitudinally extending bore for theprojection therethrough of said stud, said support member having atapered outer formation and wherein the upper portion of the supportmember is of greater diameter than the lower portion thereof, a housingmounted above said support member and said housing including upper andlower sections and an intermediate opened recess portion, a split nutmounted on said stud and arranged in the intermediate recess portion ofthe housing, a ring for engaging said split nut, a center hole jackcomprising a cylinder adapted to be connected to a source of actuatingmedium under pressure, a plunger having its lower end contiguous to thetop of the housing and said plunger having a piston portion on its upperend reciprocally engaged in said cylinder, and top nuts contiguous tothe upper end of said cylinder and said top nuts being arranged inthreaded engagement with the threaded upper sections of said stud.

References Cited in the file of this patent UNITED STATES PATENTS3,013,322 Carr Dec. 19, 1961

